The present invention relates generally to conveyor rollers and, more particularly, to axle cartridges or stub axles or axle bearing units or inserts for conveyor rollers for rotatably mounting the ends or axles of a conveyor roller to the sidewalls of the conveyor.
It is known in the roller conveyor art to mount rollers at and between the sidewalls of a conveyor frame. The rollers typically include an axle or opposite axle portions which extend into openings in the sidewalls. The rollers may have a generally cylindrical roller portion or tapered roller portion or crowned roller portion or the like which is rotatable relative to the axle or axle portions. It is also known to provide an axle bearing unit or cartridge or insert at one or both ends of a roller which provides for rotational movement of the roller portion about the respective stub axle or stub axles extending from the axle bearing unit or units. The stub axle may be spring-loaded or biased to facilitate retraction of the stub axle and to bias the stub axle to extend outwardly from the axle bearing unit for insertion into the openings in the sidewalls.
To ease insertion of the stub axle, which typically has a hexagonal-shaped cross section for insertion into a correspondingly formed hexagonally-shaped opening in the conveyor sidewall, it is known to provide a tapered end or tip at the outer end of the stub axle. The tapered end portion may also have a hexagonal-shaped cross section and may guide the stub axle into the opening and generally align the stub axle with the walls of the opening.
The present invention provides an axle bearing unit or cartridge for positioning at one or both ends of a roller portion. The axle bearing unit provides an axle portion or stub axle with guide members or ribs or ridges extending along a conical-shaped tip or end portion of the stub axle for aligning the stub axle shape or form with the correspondingly formed opening in the sidewall of the conveyor. The axle bearing unit also provides for rotational support of the roller portion about the stub axle via a bearing assembly at one end of the stub axle and further provides a support wall or member for limiting flexing or bending of the roller portion relative to the stub axle. The support member may be circumferentially spaced around the stub axle during normal operation and may contact a portion of the stub axle to limit further flexing or bending of the roller portion in response to loading of the roller portion of the conveyor roller.
According to an aspect of the present invention, an axle bearing unit or assembly or cartridge is configured to be received within an end of a roller tube or sleeve or portion of a conveyor roller. The axle bearing cartridge comprises a housing adapted to be inserted at least partially into an end of the roller portion, a stub axle or axle portion positioned partially within the housing, and a bearing assembly positioned generally at the outer end of the housing and between the stub axle and the housing to provide for rotational support of the housing about the stub axle. An inner end of the housing comprises an inner support or support member or wall. The stub axle has a longitudinal axis and extends at least partially through the inner support such that the inner support defines a gap circumferentially around the stub axle. The inner support of the housing may define the circumferential gap during operation of the roller conveyor, while a portion of the inner support may close the gap and provide contact support for the stub axle in response to loading induced deflection generally at the inner end of the housing in a direction generally normal to the longitudinal axis of the stub axle.
The inner support of the housing may define the circumferential gap during normal operation of the roller conveyor, while the portion of the inner support may close the gap in response to overloading of the roller portion of the roller, wherein the overloading may be greater than a threshold amount of loading of the roller portion.
In one form, the inner support defines an inner wall at the inner end of the housing. The inner wall defines an inner opening therethrough for receiving the stub axle at least partially therethrough. The inner opening has a diameter which is greater than a diameter of an inner axle portion of the stub axle, which may comprise a generally cylindrical inner axle portion.
In one form, an outer axle portion comprises a hexagonal-shaped cross section and a generally conical-shaped outer end. The conical-shaped outer end may comprise at least one raised rib therealong. The raised rib or ribs may be arranged on the conical-shaped outer end to be skewed or non-parallel to a plane bisecting the stub axle along the longitudinal axis of the stub axle. In other words, the raised rib or ribs may be arranged non-longitudinally along the generally conical surface of the generally conical-shaped outer end of the stub axle.
According to another aspect of the present invention, a conveyor roller for mounting at and between opposite sidewalls of a conveyor comprises a roller tube or sleeve or portion and an axle portion positioned at least partially within the roller portion and rotatable relative thereto. The axle portion defines a longitudinal axis and extends from at least one end of the roller portion. The axle portion has a generally tapered or conical-shaped outer axle end defining a generally tapered or conical-shaped surface. The outer axle end has at least one raised rib positioned along the generally conical-shaped surface of the axle end for aligning the axle portion with a respective correspondingly formed opening in a sidewall of the conveyor.
The rib or ribs may have a generally rounded cross section. The raised rib or ribs is/are arranged to be non-parallel or skewed relative to a plane bisecting the axle portion along the longitudinal axis of the axle portion. The raised ribs may comprise generally straight ribs extending along the conical-shaped surface and may define an angle between them, such as an angle of approximately 60 degrees or 120 degrees or other desired angle.
The axle portion may be axially movable relative to the roller portion between an extended position and a retracted position to ease mounting of the roller to the conveyor sidewalls. In one form, the axle portion is slidably mounted at an axle bearing unit positioned at least partially within the roller portion. The axle bearing unit may comprise a housing adapted to be inserted at least partially into the roller portion and comprising an inner support defining an opening at an inner end of the housing. The axle portion extends at least partially through the opening, wherein the opening defines a gap generally circumferentially around the axle portion. A portion of the support of the housing may close the gap and contact the axle portion in response to loading of the roller portion in a direction generally normal to a longitudinal axis of the axle portion.
Therefore, the present invention provides an axle bearing unit or assembly or cartridge which provides for rotational support of a roller portion of a roller about a stub axle or axle portion with a single bearing assembly, while limiting or substantially precluding flexing or bending of the roller and binding of the bearing assembly during excessive loading of the roller. The axle bearing unit thus provides enhanced rotation of the roller about the stub axle while substantially avoiding binding of or damage to the bearing assembly during such loading conditions. Also, the present invention provides an outer axle end of an axle portion which engages a respective opening in the sidewall of the conveyor and may cause rotation of the axle portion to align the form or shape of the axle portion with the corresponding form or shape of the opening. The outer axle end may include one or more alignment ribs or guides or members positioned along and protruding from a generally conical surface. The alignment members engage the conveyor sidewall around the respective opening and may cause rotation of the axle portion to align the axle portion with the opening as the outer axle end and axle portion are inserted into and at least partially through the opening in the conveyor sidewall.
These and other objects, advantages, purposes and features of the present invention will become apparent upon review of the following specification in conjunction with the drawings.